Light strings are used for providing decorative effect. In order to obtain a better display, a plurality of lamp shields are mounted on each light bulb as a cover. The transparent lamp shields are themselves great decorations and can show a soft lighting effect when the bulb insides is lightened. In present time, there is no suitable structure for connecting the bulb with the shield but just forcedly inserted the bulb holder into the shield. It always leads damage and the shield can not be connected with the bulb holder and hung firmly.